Israeli police searching a river yesterday pulled out a red suitcase containing a child's skull and bones, which they believe are the remains of a small girl missing for four months.

The disappearance of four-year-old Rose Pizem has gripped Israelis for weeks. The girl's mother, Marie-Charlotte Renault, 23, and paternal grandfather, Ronny Ron, 45, who were in a relationship with each other, are being held on suspicion of involvement in the murder. Ron admitted killing Rose and then later took back his confession, police said.

"We found the girl's body but it needs to undergo tests so we can be completely sure it's her," police commissioner David Cohen said at the scene. Police divers have spent several days searching through the Yarkon river after Ron told them he had dumped her body in a suitcase in the water. A postmortem examination was under way yesterday.

Rose was born in Paris in 2004, when Renault and her new husband, Benjamin Pizem, were still teenagers. After a year the couple travelled to Israel to meet Pizem's father, Ron, whom he had never met. Later Renault said she had fallen in love with Ron and stayed in Israel. Pizem returned to France with Rose.

Renault and her father-in-law had two more children. In December they won custody of Rose, who came to live with them. She was reportedly suffering several emotional and developmental problems and it appears the couple were unable to cope with the child.